1. Field of the Invention
The present invention relates to an outboard engine system in which a trim angle of a system body can be adjusted with respect to a hull by a trim device and a thrust receiver which are mounted on one and the other of the system body and a mounting device, respectively. The present invention also relates to an outboard engine system comprising a system body having a propeller shaft, and a trim device having an expandable and contractable trim rod which abuts against a thrust receiver to adjust a trim angle of the system body with respect to a hull.
2. Description of the Related Art
Such an outboard engine system is known from Japanese Patent Application Laid-open No. 8-91298 and Japanese Utility Model Application Laid-open Nos. 62-100297 and 61-132199.
In the outboard engine system described in each of Japanese Patent Application Laid-open No. 8-91298 and Japanese Utility Model Application Laid-open No. 62-100297, a tip end face of an expandable and contractable trim rod of a trim cylinder mounted on a stern bracket is in abutment against a rotatable ball of a thrust receiver mounted on a swivel case; and generation of an abnormal sound due to a twisting is prevented by rolling of the ball on the tip end face of the trim rod, when the trim rod is expanded or contracted to adjust a trim angle of a system body.
In the outboard engine system described in Japanese Utility Model Application Laid-open No. 61-132199, a ball rotatably mounted at a tip end of a trim rod of a trim cylinder is in abutment against a pressure-receiving surface of a thrust receiver; and generation of an abnormal sound due to a twisting is prevented by rolling of the ball on the pressure-receiving surface of the thrust receiver, when the trim rod is expanded or contracted to adjust a trim angle of a system body.
However, all the systems in the above-described documents have a problem of a high manufacturing cost, because they need the ball for bringing the trim rod and the thrust receiver into rolling contact with each other in order to adjust the trim angle.
In all the system in the above-described documents, although the ball is rotatably supported on a holder, a special means for smoothly rotating the ball is not provided. Fat such as grease is generally applied to sliding surfaces between the ball and the holder, but in a severe environment exposed to seawater as in the case of an outboard engine system, there is a possibility that the fat flows out in a short period to lose a lubricating effect.